Last November, a batch of newly harvested leafy vegetables hit the shelves of a campus market at National Taiwan University (NTU) in Taipei. The vegetables were guaranteed to be pesticide-free and could even be eaten without washing. Yet absent were the little holes in the leaves commonly found in vegetables from organic farms, the evidence of damage by bugs. Instead, the vegetables were so uniformly near-perfect, it seemed as if they were products of a factory rather than produce from a farm.

In fact, that is exactly the secret behind the vegetables: They were manufactured in a factory operated by NTU’s College of Bioresources and Agriculture. Currently, in addition to growing seasonal vegetables like lettuce on a year ’round basis, the factory is working on crops of high economic value such as strawberries and herbs used in traditional Chinese medicine.

Fang Wei (方煒), a professor at NTU’s Department of Bio-Industrial Mechatronics Engineering, explains that a plant factory is a closed environment in which all the elements needed for plant growth are artificially controlled, a process that removes detrimental influences such as poor weather conditions. “Traditional agriculture lives at the mercy of the elements, but a plant factory lives on science,” he says. “That is to say, we produce plants of a fixed quality, quantity, cost, time to harvest and sale price in the same way as an industrial factory produces products.”

Cleanroom Cultivation

Elements that are controlled in such plant factories include lighting, for which sunlight is replaced by fluorescent or LED (light-emitting diode) lamps, temperature, humidity, water, nutrient supply and even levels of carbon dioxide. Soil is also replaced with water or non-soil materials such as disinfected peat or other kinds of growing media to minimize the number of germs in the plants. And just like those who work in a chemical or semiconductor facility, people at the plant factory wear gloves, surgical masks and protective suits instead of the usual scruffy work clothes of most vegetable farmers. Adding it all up creates an environment where vegetables can grow about two to four times faster than by typical outdoor cultivation. “Resources that fuel plant growth are utilized in the most efficient way, and since insects and germs are effectively kept away, there’s no need for pesticides,” Fang says.

The amount, spectral output and color temperature of light can be adjusted to facilitate the growth of selected plants. (Photo by Chang Su-ching)

The concept of growing plants in a closed environment was proposed about 50 years ago and different types of factories have been developed since then. In semi-closed plant factories, plants rely solely or partially on sunlight, while in fully closed factories only artificial lighting is used. The Netherlands is the leading country in sunlight factories, while Japan has been working on artificially lit factories. In recent years, research and commercialization efforts have prioritized fully closed plant factories because of their ability to allow agricultural production in places with an extreme climate or that are subject to major temperature changes.

Plants in an artificially lit factory are grown in trays in multilayer shelves with artificial lights overhead and nutrient solutions supplied directly to their roots. This facilitates mass production in a small space, although there are some limitations on the plant varieties that can be grown this way. Tall plants, for example, cannot be grown on multilayered shelves. Taking into account the efficiency of vertical farming and  a growing facility’s immunity to unpredictable weather conditions, Fang says that the productivity per unit area in a closed-type plant factory can be 30 to 40 times higher than that for an outdoor farm.

Water is also efficiently recycled and reused in plant factories, making agriculture possible in regions with a scarce water supply or that are otherwise regarded as unsuitable for agriculture. Japan, for example, has exported plant factories built from modified shipping containers to Saudi Arabia. In these plant factories, the amount of water used for irrigation is only about 2 percent of that needed in open-field farming.

Another benefit of fully closed plant factories is their scalability, since facilities can be created to be large enough for commercial mass production or as small as a home appliance. A refrigerator-sized “factory,” for example, drew a lot of interest when it was showcased at the 2010–2011 Taipei International Flora Exposition, while Pacific Construction Co. now gives a “home factory” to buyers of its apartments as a gift. “[Having the potential] to be ubiquitous means that we could have clean vegetables grown in downtown factories or even in an apartment,” Fang says. “The carbon footprint in transporting the vegetables is therefore minimized.”

Commercial plant factories mainly grow crops with known growth variables, but the factories’ potential does not stop there. Given the closed environment, experiments can be conducted on genetically modified crops without interfering with the natural environment. In research laboratories in Japan, for example, genetically modified crops that can decrease blood pressure or hay fever symptoms have already been trialed.

Although it was not until late 2010—when the NTU facility was set up—that Taiwan had its first plant factory, local research on related techniques started around 1993, with some of the research results having been transferred from laboratories to farmers. Hydroponic agriculture, for example, has been adopted by several fruit or vegetable farms, and Taiwan’s orchid farmers have also equipped their greenhouses with temperature control devices to manipulate bloom times. Overall, however, plant factories had not drawn a lot of local interest until around three years ago.

One of the reasons for the growing attention in plant factories is people’s increasing awareness of the risk of vegetable supply shortages such as those created by climate change and more intense natural disasters. Taiwan, for example, suffers billions of dollars of agricultural losses because of typhoons or abnormal weather almost every year and prices for vegetables usually go sky--high after such events.

The fully controlled environment in a plant factory enables consistent quality and quantity of production. (Photo by Chang Su-ching)

Another reason for the interest in manufactured vegetables and fruit is higher food safety standards. As the negative impact of pesticides and chemicals on human health has become a concern, organic food has risen in popularity. But organic vegetables have their own risks. Fang explains that the nitrogen-based fertilizers often used in organic farming can result in high levels of nitrates—a suspected cause of cancer—in plants if there is not enough sunlight in the growing process. While nitrates exist in all vegetables, they are guaranteed to be kept at a safe level in a plant factory. “Organic vegetables are not always healthy and they sure look ugly, but our vegetables are guaranteed healthy and look good,” Fang says.

A key factor that has really hastened the development of plant factories is the advancement of related technologies. Take lighting, for example. High pressure sodium lamps were used initially, but the amount spent on air conditioning to reduce the heat generated by such lamps was high. The availability of T5 and LED lights in recent years has greatly helped reduce air conditioning expenses, a cost that can be cut further with electricity generated from solar power. T5 lights are a thinner kind of fluorescent tube that enables better photo-optic control of light, increases efficiency and provides uniform distribution of light output.

“Technological advances like these turn plant factories from ‘technically feasible to ‘economically viable,’” Fang says. “And Taiwan’s solid background in related technologies—photovoltaic, LED, information science—enables us to play a leading role in the development of the industry.”

Big Investment

The development of plant factories, on the other hand, is not without challenges. Shih Jau-chang (施昭彰), a researcher at the Taiwan Agricultural Research Institute, notes that one of the problems is that building and operating a fully closed plant factory requires a substantial investment. When farmers in Taiwan are able to supply the market with traditional farming techniques, there seems to be no need for them to invest in plant factories. Fang agrees that while the production cost for a plant factory has been brought down considerably in recent years, the investment required, especially for electricity, is still prohibitively high. Therefore, such operations are more suitable for large enterprises than individual farmers, he says.

In fact, several non-agriculture-related companies have already set up their own plant factories. LED manufacturer Everlight Electronics, for example, has built a plant factory in Tucheng, New Taipei City to conduct research on LED applications for growing plants. Other high-tech companies such as Inventec and Foxconn have also set up facilities or shown an interest in doing so. In June 2011, the Industrial Technology Research Institute got together with more than 20 businesses and academic research institutions to establish the Taiwan Plant Factory Industry Development Association. By building a platform for cross-industry collaboration, the organization aims to help Taiwan’s industries enter and create opportunities in the field.

Obviously, most of the businesses involved so far know more about high-tech equipment than farming and are concerned more about cultivating new markets for their technology products than selling vegetables. The resources they contribute can nevertheless speed the development of plant factories. “The beauty of a plant factory is that you don’t need to know agriculture to run it,” Fang says. “It’s like an automated production line, where you just need to key in the data, put in the raw materials and you can get completed products at the other end of the line.”

While traditional outdoor farming exists at the mercy of the elements, a fully closed plant factory where all the elements are controlled is run on science. (Photo by Chang Su-ching)

Cost to Consumers

Huang Li-chun (黃麗君), an assistant professor in NTU’s Department of Bio-Industry Communication and Development, notes that a survey conducted in Japan in 2009 showed that only 3 percent of consumers were willing to pay more for vegetables from plant factories, while 59 percent would only make a purchase if the produce was cheaper than that from traditional farms. Another survey carried out a few months later, however, showed that 90 percent of consumers would buy plant factory products if the price was less than 20 percent higher than those from traditional farms. In Taiwan, a survey conducted by Huang suggests that local consumers care more about energy consumption and pollution control in the production process than prices.

Fang agrees that price is not the only reason behind purchase decisions, as there are always people who are willing to pay more for quality products. Top quality imported vegetables with prices four times those of products from the NTU plant factory, for example, sell easily in some supermarkets. The challenge is in changing people’s minds. In a survey conducted by the Japanese government, while endorsing the look and safety of plant factory vegetables, many Japanese consumers suspected them to be less nutritious and found them less tasty than those produced by traditional farming. “Scientifically, crops from a plant factory are in every way better than those from open fields,” Fang says. “But in many people’s minds, something’s got to be fishy if it’s not rooted in solid soil and grown under sunlight.”

Considering the higher production cost, plant factories currently only grow high value crops. They are clean, safe and the process of production is environmentally friendly, but people would be unable to meet all their dietary needs by relying on the limited selection of crops from plant factories. “The bottom line is that plant factories are not meant to replace traditional agriculture,” Fang says. “They’re simply offering an alternative way to deal with some of the difficulties faced by traditional agriculture.”

Write to Jim Hwang at jim@mail.gio.gov.tw